JP2006115612A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor with rigidity against a radial load that acts on a rotating shaft. <P>SOLUTION: A bearing support part 14 is integrally formed almost at the center of the closing-side end face of a yoke housing 4. The bearing support part 14 comprises a double wall 2 that is closely contact with the bearing support in the radial direction from the axial tip toward the base end of the support part in a state that the double wall is folded at the opening side of the support part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor.

  Various mechanisms such as ABS (anti-lock brake system) are mounted on automobiles. Some of these mechanisms obtain driving force directly from the engine, but many of them are driven and controlled by motors.

By the way, in recent years, miniaturization of each of these mechanisms and simplification of the shape have been particularly demanded in order to reduce the size of an automobile or mount further mechanisms.
For example, the piston pump is formed long in the radial direction of the rotating shaft in order to convert the driving force of the motor into a reciprocating motion. For this reason, the motor projects from the piston pump substantially vertically, and interference with other mechanisms becomes a problem. Therefore, the length of the rotating shaft of the motor is largely related to the downsizing and simplification of the shape of the piston pump. That is, shortening the rotation axis of the motor is effective for miniaturization and simplification of the mechanism.

  The length of the rotating shaft of the motor is almost equal to the commutator, the core around which the winding is wound, the overhang of the winding wound around the core in the axial direction, the thickness of the case, and the bearing that supports the rotating shaft. It is determined. Therefore, the problem is how to shorten the rotation axis without interfering with these structural requirements.

In order to solve such a problem, for example, in Patent Document 1, a commutator is formed on the inner side of the core, so that the length of the commutator in the axial direction of the rotating shaft is not required and the shaft is shortened. A motor is disclosed.
Japanese Patent Laid-Open No. 10-248225

  However, when receiving a load in the radial direction on the output side of the rotating shaft, such as a motor that drives a piston pump, if the rotating shaft is shortened, a large reaction force against the load is applied to the bearing that supports the non-output side of the rotating shaft. Works. Therefore, in order to suitably transmit the driving force, it is necessary to increase the structural strength against the radial load of the bearing support portion that supports the bearing.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a motor having strength against a radial load acting on a rotating shaft.

  In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that a core around which a winding is wound, a cylindrical shape and an outer peripheral surface thereof arranged at a predetermined interval and electrically connected to the winding. A commutator having commutator pieces connected to each other, a rotary shaft in which the commutator and the core are disposed, and rotating integrally therewith, and a first bearing and a second bearing that support the rotary shaft, A motor comprising a brush that is in sliding contact with the commutator piece, a yoke that encloses a magnet that applies a magnetic field to the core, and an end plate that closes the opening of the yoke and has a through hole through which the rotating shaft passes. The yoke includes a bearing support portion that protrudes annularly from the bottom to the opening side and holds the outer ring of the first bearing, and the bearing support portion has a multilayer structure in which at least a part thereof is in close contact with the radial direction. It has.

According to a second aspect of the present invention, in the motor of the first aspect, the bearing support portion has a two-layer structure, and at least a part of each layer in the axial direction is formed in close contact with each other in the radial direction.
According to a third aspect of the present invention, in the motor according to the second aspect, the bearing support portion includes a cylindrical first wall extending from the bottom portion toward the opening, and the first wall. A second wall that is in close contact with the substantially central portion from the distal end in the axial direction and is separated from the first wall toward the proximal end portion.

  According to a fourth aspect of the present invention, in the motor according to any one of the first to third aspects, the yoke includes an inner peripheral side bottom portion radially inward of the bearing support portion, and the bearing support portion. The outer peripheral side bottom portion on the outer side in the radial direction is formed on substantially the same plane.

  According to a fifth aspect of the present invention, in the motor according to any one of the first to fourth aspects of the present invention, the core has a housing portion in which at least one axial end surface is recessed along the rotational axis. And part or all of at least one of the first bearing and the commutator is accommodated in the accommodating portion.

  According to a sixth aspect of the present invention, in the motor according to any one of the first to fifth aspects, the rotating shaft is biased toward the output side by an elastic member disposed on the opposite side to the output side. The outer shape of the commutator is larger than the outer diameter of the second bearing disposed on the output side, and the inner diameter of the through hole is smaller than the outer diameter of the commutator.

  According to a seventh aspect of the present invention, in the motor according to any one of the first to sixth aspects, the through-hole holds the second bearing on an inner peripheral side thereof, and the shaft of the through-hole The length in the direction is smaller than the axial thickness of the second bearing.

(Function)
According to invention of Claim 1, the intensity | strength with respect to a radial direction load can be raised by making a bearing support part into a multilayer structure.

  According to invention of Claim 2, the intensity | strength with respect to the load of radial direction can be raised by making a bearing support part into a double wall. The double wall can be easily formed by reverse drawing or the like. That is, it is possible to easily form a shaft accommodating portion having strength against a radial load.

  According to the third aspect of the present invention, the second wall is brought into close contact with the cylindrical first wall from the front end of the bearing support portion to the substantially center in the axial direction, and separated toward the base end portion. The protruding length in the axial direction of the portion closely contacting in the radial direction is shortened. When the bearing receives a load in the radial direction, if the protrusion length is long, the moment acting on the base end portion becomes large. Therefore, it is possible to have more strength against radial loads by shortening the protruding length.

According to the invention described in claim 4, by forming the non-output surface side on substantially the same plane, the shape is simplified, and interference with other mechanisms or members can be prevented.
According to the fifth aspect of the present invention, at least a part of the bearing or the commutator can be accommodated in the accommodating portion formed in the core. Therefore, since the total value of the lengths in the longitudinal direction of the rotating shafts of the core and the bearing is smaller than the case where it is not accommodated, the length of the rotating shaft can be shortened. Moreover, since the commutator formed in the column shape can be used, it has versatility.

  According to the sixth aspect of the present invention, the rotational shaft can regulate the axial movement because the commutator and the end plate are in contact with each other even if the axial movement of the output-side bearing is not restricted when assembled. it can.

  According to the seventh aspect of the present invention, the thickness of the end plate that closes the output side of the rotating shaft is included in the axial thickness of the output side bearing. That is, the output side bearing and the end plate are not stacked in the axial direction. Therefore, the rotating shaft can be shortened.

  ADVANTAGE OF THE INVENTION According to this invention, the motor provided with the intensity | strength with respect to the load of the radial direction which acts on a rotating shaft can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows a pump device 1 using a motor according to the present embodiment. 1A is a partial sectional view showing an embodiment of the present invention, and FIG. 1B is a partially enlarged view of FIG.

  The pump device 1 includes a motor unit 2 as an electric motor and a pump unit 3 that pumps fluid. Here, for simplification of description, in the motor unit 2 shown in FIGS. 1 and 2, the left side (the pump unit 3 side) is the output side, and the right side is the non-output side.

  As shown in FIG. 1A, the motor unit 2 includes a yoke housing 4 formed in a substantially bottomed cylindrical shape, a rotor 5 accommodated in the yoke housing 4, and a resin that closes the opening of the yoke housing 4. And an end plate 6 made of metal. The opening of the yoke housing 4 is formed on the output side (the pump unit 3 side) of the rotor 5.

  A magnet 7 is fixed to the inner peripheral surface of the yoke housing 4, and the rotor 5 is rotatably supported facing the magnet 7. The rotor 5 is rotatable about a rotation shaft 8, and a commutator 9 and an armature 10 are fixed to the rotation shaft 8 so as to rotate integrally. The commutator 9 is in sliding contact with a brush 11 provided on the rotor 5 side of the end plate 6, and the armature 10 is rotated by power feeding from the brush 11.

  The rotating shaft 8 includes an anti-output side bearing 12 as a first bearing disposed on the counter-output side from the armature 10 in the axial direction, and an output side as a second bearing disposed on the output side from the commutator 9. The bearing 13 is rotatably supported. The non-output side bearing 12 is accommodated in a bearing support portion 14 formed at the center of the bottom of the yoke housing 4, and the output side bearing 13 is held by a holding portion 15 disposed at the center of the end plate 6.

  A countersunk spring 16 as an elastic member is disposed on the opposite end of the rotary shaft 8, that is, the bearing support 14, and the armature 10, the commutator 9, the output side bearing 13, and the counter output side bearing 12 rotate. The shaft 8 is urged together with the output side.

  The yoke housing 4 includes a flange portion 17 that is formed at an opening end portion thereof and extends substantially perpendicularly to the outside in the radial direction, and includes a bearing support portion 14 that supports the non-output-side bearing 12 at a substantially central portion of the bottom portion ( (See FIG. 3).

  The bearing support portion 14 protrudes from the bottom of the yoke housing 4 to the output side and is folded back at the end thereof. The first wall 18 that forms the inner peripheral wall of the bearing support portion 14 and the first wall 18 that forms the outer peripheral wall of the bearing support portion 14. The two walls 19 have a two-layer structure in the radial direction from the axial front end to the base end. The counter-output side bearing 12 is held in contact with the first wall 18. An inner peripheral side bottom portion 20 where the disc spring 16 is disposed continuously from the first wall 18 of the bearing support portion 14 and an outer peripheral side bottom portion continuous from the base end portion of the second wall 19 of the bearing support portion 14 to the outer diameter side. 21 is formed on substantially the same plane. The yoke housing 4 is integrally formed from a metal material by pressing.

  A step portion 22 is formed on the inner periphery of the yoke housing 4 near the opening. On the opening side from the step portion 22 is an end plate fitting portion 24 that fits the end plate 6 in which the brush holder 23 is fitted. The end plate 6 is inserted into the insertion direction by the step portion 22. Displacement is regulated.

  In the end plate 6, a holding portion 15 that holds the output-side bearing 13 is formed to protrude at a substantially central portion of the output-side surface, and a through-hole 25 that penetrates the end plate 6 is formed in the holding portion 15. ing. Further, a brush holder 23 that holds the brush 11 that is in sliding contact with the commutator 9 is formed integrally with the end plate 6 on the surface on the opposite side of the end plate 6. The end plate 6 is made of resin, and the end plate 6, the brush holder 23, and the holding portion 15 are formed by integral molding. Here, the brush 11 is accommodated in the brush holder 23 and is urged toward the opening side, that is, the commutator 9 side by a spring disposed at the bottom of the closing side.

  The diameter of the through hole 25 of the holding part 15 is slightly smaller than the outer shape of the insulating part 26 of the commutator 9 and slightly larger than the output side bearing 13. Further, since the axial thickness of the holding portion 15 is smaller than the axial thickness of the output side bearing 13, the output side bearing is in a state where the insulating portion 26 is in contact with the surface on the opposite side of the holding portion 15. 13 projects from the end plate 6, that is, the motor unit 2 to the output side. Further, since the output side bearing 13 is disposed on the radially inner side of the holding portion 15, the output side bearing 13 and the holding portion 15 overlap in the axial length.

  In addition, the end plate 6 is integrally formed with the end plate holding portion 27 below the through hole 25 in the state shown in FIG. 1A so as to protrude from the output side surface of the end plate 6 to the axial output side. Has been. Embedded in the end plate holding portion 27 is a wiring / use plate 28 having one end electrically connected to the brush 11. The end plate 6 is fixed to the pump device 1 with the end plate holding portion 27 fixed to a pump housing 29 described later.

The output side surface of the flange portion 17 of the yoke housing 4 and the output side surface of the end plate 6 are formed so as to be substantially in the same plane.
One end of the rotating shaft 8 protrudes from the through hole 25 of the end plate 6, and an eccentric portion 8a is formed in the protruding portion. The eccentric portion 8 a is formed in a cylindrical shape having a center different from that of the rotation shaft 8. Further, a bearing 30 is disposed in the eccentric portion 8a. For this reason, when the rotating shaft 8 rotates, the bearing 30 moves eccentrically. The pump housing 29 is formed with a rotation shaft accommodating portion 29 a along the protrusion of the rotation shaft 8 for allowing the eccentric portion 8 a to rotate eccentrically.

  The commutator 9 includes an insulating portion 26 formed in a cylindrical shape from an insulating resin and the like, and commutator pieces 9a disposed on the outer periphery thereof at equal intervals. The outer diameter of the insulating portion 26 is slightly larger than the inner periphery of the through hole 25 formed in the end plate 6. The commutator 9 is fixed to the rotary shaft 8 so that the brush 11 held by the brush holder 23 and the commutator piece 9a are in sliding contact. That is, the commutator 9 is disposed on the side opposite to the output surface of the end plate 6 at an axial position corresponding to the end plate fitting portion 24 formed inside the opening of the yoke housing 4.

  The armature 10 is formed in a substantially columnar shape, and a plurality of teeth portions 10a protruding outward in the radial direction are formed on the outer circumferential surface at equal angular intervals along the circumferential direction. The teeth portion 10a is formed in a substantially T shape with radial ends extending on both sides in the circumferential direction, and a winding 10b is wound around the teeth portion 10a. Further, the bottom surface on the counter-output side is provided with a receiving portion 31 that is recessed on the output side.

  The accommodating portion 31 includes a bottom portion 31a on the output side, and a shaft hole 31b having the same diameter as that of the rotary shaft 8 is formed in the approximate center of the bottom portion 31a. The bottom portion 31a has a larger diameter than the bearing support portion 14 that supports the counter-output side bearing 12 formed in the yoke housing 4, and a receiving surface 31c is formed from the circumference thereof vertically toward the counter-output side. . The non-output-side bearing 12 is housed in the bearing support portion 14 and in the housing portion 31 of the armature 10. For this reason, the non-output side bearing 12 and the armature 10 wait for overlap in the axial length.

  Here, as shown in FIGS. 2A and 2B, in the motor unit 2 alone, the bearing 30, the output side bearing 13, the commutator 9, the armature 10, and the counter-output side bearing are urged by the biasing force of the disc spring 16. Since 12 is urged to the output side integrally with the rotating shaft, the insulating portion 26 is in contact with the end plate 6 (see FIG. 2B). That is, the bearing 30 and a part of the output side of the output side bearing 13 protrude from the motor portion 2, and the axial movement is prevented by the contact between the holding portion 15 and the insulating portion 26 of the commutator 9. . In addition, since the output side bearing 13 has a smaller diameter than the through hole 25, press fitting is not required, and it is easily inserted into the holding portion 15 and assembled.

  On the other hand, as shown in FIG. 1A, the pump unit 3 includes a pump housing 29, and the pump housing 29 has a rotating shaft housing portion 29 a that allows the eccentric portion 8 a to move eccentrically. It is formed in a manner extending in the direction. The rotary shaft accommodating portion 29 a is open toward the pump portion 3 side and includes a bearing support surface 29 b that fits with the output side bearing 13.

  The bearing support surface 29b is recessed in the radial direction from the rotary shaft housing portion 29a, and the output side bearing 13 is located on the contact surface 29c that is a surface perpendicular to the axial direction from the bearing support surface 29b to the rotary shaft housing portion 29a. It is in contact with the pump housing 29. Further, the opening side from the contact surface 29 c is recessed according to the protrusion of the end plate 6. In other words, the rotary shaft 8 urged to the output side by the disc spring 16 is pushed back to the non-output side when the abutment surface 29c and the bearing support surface 29b abut on the output side bearing 13 (FIG. 1B). reference). When the rotary shaft 8 is pushed back, the insulating portion 26 is separated from the end plate 6 and the output side bearing 13 is restricted from being displaced in the radial direction by the bearing support surface 29 b of the pump portion 3.

  With the configuration as described above, as shown in FIG. 1A, the pump unit 3 and the motor unit 2 are integrally fixed by bolts, electric power is supplied from the brush 11, the rotor 5 is rotated, and the plunger 32 is reciprocated. The fluid is pumped by changing the volume of the hydraulic part 33.

As described above, the present embodiment has the following effects.
(1) Since the bearing support portion 14 formed on the yoke housing 4 is formed with a double wall closely in the radial direction, the strength against the radial load is increased. Further, it is possible to easily form the bearing support portion 14 by reverse drawing processing so that the bearing support portion 14 protrudes from the closed portion of the yoke housing 4 to the output side and is folded back on the opening side.

  (2) By forming the accommodating portion 31 on the axially opposite output side end face of the armature 10, the opposite output side bearing 12 can be accommodated. With such a configuration, the armature 10 and the counter-output side bearing overlap in the axial direction, and the rotating shaft 8 can be shortened.

  (3) Since the output side bearing 13 has a smaller diameter than the through hole 25, only the radial displacement is restricted by the holding portion 15. Therefore, it is not necessary to press fit, and assembly is easy. As shown in FIG. 2, in the motor unit 2 alone, the insulating unit 26 and the holding unit 15 are in contact with each other in the axial direction, thereby preventing the rotating shaft 8 from protruding to the output side. However, as shown in FIG. 1, when integrated with the pump unit 3, the output side bearing 13 is pushed back to the non-output side by the pump housing 29 (the bearing support surface 29b and the contact surface 29c). It is separated from the holding part 15. Therefore, the rotor is supported only by the bearing and does not hinder rotation.

  (4) The holding portion 15 only supports the output side bearing 13 from the radial direction, and the output side bearing 13 projects from the end plate 6 to the output side. Therefore, since the end plate 6 and the output side bearing 13 are not stacked in the axial direction, the rotating shaft 8 is shortened.

  (5) The outer peripheral side bottom portion 21 and the inner peripheral side bottom portion 20 which are the bottom portions of the yoke housing 4 are formed on substantially the same plane. That is, the yoke housing 4 has a simple flat surface on the side opposite to the output side, so that interference with other mechanisms is prevented.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the bearing support portion 14 is doubled in the radial direction from the tip end in the axial direction to the base end portion in a manner of being folded back on the opening side. However, as shown in FIG. 4, a double wall is in close contact from the axial front end of the bearing support portion 14a to the substantially central portion thereof, and the base end portion of the second wall 19a is widened radially outward. You can also. According to such a configuration, the bearing support portion 14 a can support the axial width center portion of the non-output-side bearing 12. Therefore, it can have more strength against radial displacement. Further, in such a configuration, as shown in FIG. 5, a double wall is in close contact from the axial front end of the bearing support portion 14b to the substantially central portion, and the base end portion of the second wall 19b is radially outward. It is also possible to adopt an aspect in which it is formed at a substantially right angle. According to such an aspect, the radial load acting on the bearing support portion 14b is more reliably supported by the yoke housing 4, and the strength against the more radial load can be provided.

Further, not only double walls but also multiple walls are formed in the radial direction to form a multi-layer structure, so that more strength can be provided.
In the above embodiment, the accommodating portion 31 is formed by recessing the non-output side of the armature 10. However, the receiving portion may be formed by recessing the output side. In this case, what is accommodated in the accommodating portion is a hook portion 9b in which the winding 10b is connected to the commutator 9 and becomes the maximum outer diameter portion.

(A) Sectional drawing which shows this Embodiment, (b) The elements on larger scale of the figure (a). (A) Sectional drawing which shows this Embodiment, (b) The elements on larger scale of the figure (a). The side view which shows this Embodiment. The partial cross section figure which shows another example. The partial cross section figure which shows another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... York housing, 6 ... End plate, 8 ... Rotating shaft, 9 ... Commutator, 9a ... Commutator piece, 10 ... Armature, 10a ... Teeth part, 10b ... Winding, 11 ... Brush, 12 ... 1st bearing Anti-output-side bearing, 13 ... Output-side bearing as second bearing, 14, 14a, 14b ... Bearing support, 18 ... First wall, 19, 19a, 19b ... Second wall, 20 ... Inner peripheral side bottom 21 ... Outer peripheral side bottom part, 25 ... Through hole, 31 ... Storage part, 31a ... Bottom part.

Claims (7)

A core wound with windings;
A commutator having a commutator piece formed in a cylindrical shape and disposed on the outer peripheral surface thereof at a predetermined interval and electrically connected to the winding;
The commutator and the core are disposed, and a rotating shaft that rotates integrally therewith,
A first bearing and a second bearing for supporting the rotating shaft;
A brush in sliding contact with the commutator piece;
A yoke containing a magnet for applying a magnetic field to the core;
An end plate having a through hole that closes the opening of the yoke and through which the rotation shaft passes,
The yoke includes a bearing support portion that projects annularly from the bottom to the opening side and holds the outer ring of the first bearing,
The motor is characterized in that the bearing support part has a multilayer structure in which at least a part thereof is in close contact with the radial direction. The motor according to claim 1,
The motor is characterized in that the bearing support portion has a two-layer structure, and at least a part of each layer in the axial direction is formed in close contact with each other in the radial direction. The motor according to claim 2,
The bearing support portion has a cylindrical first wall extending from the bottom toward the opening,
A motor comprising: a second wall that is in close contact from the axially leading end of the first wall to a substantially central portion thereof and that is separated from the first wall as the base end portion is reached. The motor according to any one of claims 1 to 3,
The motor is characterized in that an inner peripheral bottom portion radially inward from the bearing support portion and an outer peripheral bottom portion radially outward from the bearing support portion are formed on substantially the same plane. The motor according to any one of claims 1 to 4,
The core includes an accommodating portion in which at least one end surface in the axial direction is recessed along the rotation axis,
A motor in which a part or all of at least one of the first bearing and the commutator is housed in the housing portion. In the motor according to any one of claims 1 to 5,
The rotating shaft is biased to the output side by an elastic member disposed on the opposite output side,
The outer shape of the commutator is larger than the outer diameter of the second bearing disposed on the output side,
The motor according to claim 1, wherein an inner diameter of the through hole is formed smaller than an outer diameter of the commutator. The motor according to any one of claims 1 to 6,
The through hole holds the second bearing on the inner peripheral side thereof,
The length of the through hole in the axial direction is smaller than the axial thickness of the second bearing.

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